Table 1.
Characteristics of study participants at randomization.
| Control (n=68) | Lottery (n=67) | Reminder (n=67) | Lottery + Reminder (n=68) | |
|---|---|---|---|---|
| Demographic characteristics | ||||
| Age, median (IQR), years | 64.0 (60.0–71.0) | 62.0 (51.0–68.0) | 62.0 (55.0–67.0) | 61.5 (51.5–68.5) |
| Female sex, n (%) | 23 (34) | 21 (31) | 17 (25) | 25 (37) |
| African American race, n (%) | 46 (68) | 54 (81) | 44 (67) | 52 (78) |
| Completed high school, n (%) | 45 (66) | 29 (43) | 33 (49) | 29 (43) |
| Employment status, n (%) | ||||
| Working | 8 (12) | 6 (9) | 8 (12) | 10 (15) |
| Unemployed | 3 (4) | 9 (13) | 5 (8) | 2 (3) |
| Retired | 30 (44) | 33 (49) | 27 (40) | 23 (34) |
| Disabled | 27 (40) | 19 (28) | 27 (40) | 33 (49) |
| Household income, n (%) | ||||
| <100% of federal poverty level | 14 (22) | 20 (31) | 18 (29) | 25 (37) |
| 100–200% of federal poverty level | 25 (39) | 20 (31) | 19 (30) | 22 (33) |
| Control (n=68) | Lottery (n=67) | Reminder (n=67) | Lottery + Reminder (n=68) | |
| 200–300% of federal poverty level | 9 (14) | 14 (22) | 14 (22) | 8 (12) |
| >300% of federal poverty level | 16 (25) | 11 (17) | 12 (19) | 12 (18) |
| Insurance statusa | ||||
| Medicaid, n (%) | 10 (15) | 8 (12) | 9 (14) | 14 (21) |
| Medicare, n (%) | 40 (59) | 33 (51) | 27 (42) | 27 (40) |
| Private, n (%) | 28 (41) | 22 (34) | 26 (41) | 26 (38) |
| VA, n (%) | 30 (44) | 28 (43) | 22 (34) | 23 (34) |
| Other, n (%) | 0 (0) | 3 (5) | 1 (2) | 0 (0) |
| None, n (%) | 0 (0) | 1 (1) | 2 (3) | 2 (3) |
| Marital status, n (%) | ||||
| Currently married | 26 (39) | 28 (42) | 25 (38) | 18 (27) |
| Separated, divorced, or widowed | 27 (40) | 27 (40) | 30 (46) | 34 (51) |
| Never married | 14 (21) | 12 (18) | 11 (16) | 15 (22) |
| Warfarin therapy | ||||
| Indication for warfarin therapy a | ||||
| Atrial fibrillation or flutter | 37 (56) | 31 (47) | 33 (50) | 30 (45) |
| Deep vein thrombosis or pulmonary embolism | 19 (29) | 27 (41) | 20 (30) | 21 (31) |
| Mechanical heart valve | 9 (14) | 0 (0) | 7 (11) | 5 (8) |
| Other | 20 (30) | 21 (32) | 21 (32) | 24 (36) |
| Prior warfarin use | 13 (19) | 16 (24) | 14 (21) | 16 (24) |
| Target INR range, n (%) | ||||
| 2.0–3.0 | 60 (88) | 65 (97) | 59 (88) | 65 (96) |
| 2.5–3.5 | 8 (12) | 2 (3) | 8 (12) | 3 (4) |
| INR at enrollment, n (%) | ||||
| Below range | 13 (19) | 14 (21) | 15 (22) | 14 (21) |
| In range | 55 (81) | 53 (79) | 52 (78) | 54 (79) |
| DASS score, median (IQR) | 50.0 (42.5–66.0) | 50.0 (39.0–65.0) | 48.0 (40.0–63.0) | 52.0 (44.5–68.4) |
| Control (n=68) | Lottery (n=67) | Reminder (n=67) | Lottery + Reminder (n=68) | |
| Medical history | ||||
| Body mass index, median (IQR), kg/m2 | 29.4 (25.8–34.8) | 29.2 (24.6–32.3) | 29.3 (26.7–35.0) | 30.6 (26.7–34.7) |
| Smoking status, n (%) | ||||
| Current | 7 (10) | 15 (22) | 15 (22) | 15 (22) |
| Former | 36 (53) | 28 (42) | 27 (40) | 32 (47) |
| Never | 25 (37) | 24 (36) | 25 (37) | 21 (31) |
| History of congestive heart failure, n (%) | 26 (38) | 23 (34) | 28 (42) | 19 (28) |
| History of diabetes mellitus, n (%) | 20 (29) | 18 (27) | 27 (40) | 31 (46) |
| History of hypertension, n (%) | 56 (82) | 47 (70) | 51 (76) | 52 (77) |
| History of myocardial infarction, n (%) | 14 (21) | 13 (20) | 13 (20) | 13 (19) |
| History of stroke, n (%) | 18 (27) | 14 (21) | 13 (19) | 9 (13) |
| General health status, n (%) | ||||
| Excellent | 1 (1) | 3 (4) | 1 (2) | 2 (3) |
| Very good | 8 (12) | 5 (7) | 10 (15) | 8 (12) |
| Control (n=68) | Lottery (n=67) | Reminder (n=67) | Lottery + Reminder (n=68) | |
| Good | 21 (31) | 28 (42) | 25 (37) | 22 (32) |
| Fair | 30 (44) | 26 (39) | 27 (40) | 34 (50) |
| Poor | 8 (12) | 5 (7) | 4 (6) | 2 (3) |
| Short form (SF-36) health survey | ||||
| Physical score, median (IQR) | 36.7 (29.0–43.7) | 36.6 (28.6–45.9) | 39.4 (33.6–47.6) | 36.7 (29.1–43.8) |
| Mental score, median (IQR) | 51.6 (41.0–59.0) | 53.2 (42.6–59.3) | 51.3 (43.4–57.3) | 52.3 (46.8–59.1) |
| CCSE score, median (IQR) | 27.0 (23.5–29.0) | 26.0 (23.0–29.0) | 27.0 (24.0–29.0) | 27.0 (24.0–29.0) |
IQR, inter-quartile range (25th-75th percentile); CCSE, Cognitive Capacity Screening Examination; DASS, Duke Anticoagulation Satisfaction Survey
a
Participants could report more than one source of health insurance and more than one indication for warfarin therapy.